Many pigment-based ink compositions for inkjet printing using various solvents have been proposed thus far. When used in printing printed matter, however, these pigment-based ink compositions tend to clog nozzles of inkjet printers, resulting in printed matter with decreased printing quality. Also, the printed matter printed using such pigment-based ink compositions may not necessarily achieve sufficient color expression.
In particular, ink compositions using strong organic solvents, acidic or basic pigments and other additives are likely to corrode the nozzles of a printer head, providing a major cause of nozzle clogging.
PTL 1 discloses a technique to prevent corrosion of electrodes mounted on a piezoelectric element by using an ink composition containing an ethanolamine compound. When added to an ink, however, these anticorrosive agents can cause pigments or resins dispersed in the ink to coagulate and clog nozzles during long-term storage. Thus, such inks have unfavorable dispersion stability.